Textile drafting apparatus



March 28, 1967 w. P. WARTHEN TEXTILE DRAFTING APPARATUS 2 Sheets-Sheet 1 Original Filed March 25, 1963 INVENTOR. WILLIAM P. WARTHEN BY ATTORNEY- W. P. WARTHEN March 28, 1967 TEXTILE DRAFTING APPARATUS 2Sheets-Sheet 2 Original Filed March 25, 1963 INVENTOR. WILLIAM P. WARTHEN BY L it/XL,

ATTORN E Y United States Patent 3,310,346 TEXTELE DRAFTZNG APPARATUS Wiliiarn I. Warthen, Spartaubnrg, S.C., assignor to Deering Miiliiien Research Corporation, Spartanburg, S.C., a corporation of Delaware Original application Mar. 25, 1963, Ser. No. 267,541, now Patent No. 3,254,375, dated June 7, 1966. Divided and this application June 10, 1965, Ser. No. 462,900 6 Claims. (Cl. 19-453) This application is a division of copending application Ser. No. 267,541, filed Mar. 25, 1963, now Patent No. 3,254,375.

This invention relates to an improved textile processing apparatus, and more particularly to an improvement in textile drafting or drawing apparatus.

It is common practice in the textile art to draft or draw a bundle of staple fibers into a smaller size bundle by employing increasingly faster driven pairs of drafting rolls in sequential order. It has also been conventional practice to employ aprons about one or more pairs of these rolls in order to provide better control of the fibers in the draft zone between the succeeding pairs of rolls. In employing such aprons it has been the conventional practice to utilize one or more internal apron reversing nose bars or tensor elements spaced from the respective rolls and disposed in guiding relation within the respective aprons. It has also been proposed in US. Patent 1,213,744, toemploy external pressure elements in the form of rods or rollers in pressure contact with the outer surfaces of the return runs of the aprons. However, this prior art proposal of external pressure elements has been deficient in that the external pressure elements which are employed for deflecting the apron or aprons are subject to considerable linting or lint accumulation due to their extending across the complete width of the apron or aprons. Thus, any lint which may be carried by the external surface of the apron as the apron leaves the fiber control zone at the nose reversal point will thereupon be brought into engagement with the external pressure element and in most instances will be stopped by this external pressure element and accumulate thereat. After a period of time this accumulation of lint may be quite troublesome, requiring operator cleaning. Also, the accumulation of this lint may interfere with the normal operation of the apron prior to any substantial accumulation thereof. It is a feature of the present invention that this deficiency of the prior art is overcome.

Still other objects, features and attendant advantages will become apparent to those skilled in the art from the foregoing detailed description of several illustrative embodiments constructed in accordance with the invention, taken in conjunction with the accompanying drawings wherein:

FIGURE 1 is a partially cutaway view in perspective of a drafting cradle arrangement constructed in accordance with the present invention.

FIGURE 2 is a longitudinal section view of the arrangement of FIGURE 1.

FIGURE 3 is a perspective view of the cradle of FIG- URE 1 without the rolls or aprons on which the cradle is conventionally mounted for running operation.

FIGURES 4 and 5 are perspective views similar to FIGURE 1 of modifications according to the invention.

FIGURES 6 and 6a are perspective views of another cradle assembly and the cradle used therein, respectively.

FIGURES 7a and 7b are perspective views of another cradle assembly and FIGURE 8 is a transverse sectional view taken along line VIII-VIII of FIGURE 7a of the assembly mounted for operation.

FIGURES 9a and 9b are perspective views of still another cradle assembly and FIGURE 10 is a cross-sectional view taken along line lX-IX' of FIGURE 9a of the assembly mounted for operation.

Referring now in detail to the figures of the drawing, in the embodiment of FIGURES l3 there is provided a cradle assembly 11 for mounting on a pair of upper and lower conventional drafting rolls 13, 15 which may constitute one pair of several succeeding sets of drafting rolls as in conventional practice, the other pairs of drafting rolls being normal-1y disposed in spaced relation preceding and subsequent to the rolls 13, 15.

The drafting cradle assembly 11 is illustrated as including side plates 17, 19, which are connected together by spacer elements 21, 23 secured to or formed as an integral part of the side plates 17, 19. Fiber control aprons 25, 27 are disposed about a portion of the peripheral surface of each of the drafting rolls 13, 15, and extend outwardly from the roll surfaces toward a succeeding pair of rolls, now shown, to form interfacing apron fiber control runs 25a and 27a. The direction of rotation of the upper roll 13 is counterclockwise as viewed in FIG- URE 1, and the direction of rotation of roll 15 is clockwise, whereby the fiber control runs 25a, 27a are pushed forward away from the nip formed between the rolls 13 and 15 to a reversal zone where the aprons form a bulbshaped nose 25b, 2719 as a result of this pushing action on the aprons as well as the pulling action exerted on the return runs 250, 27c of the two aprons by the rolls 13 and 15, and the provision of side guide pressure elements 11a, 11b which serve to deflect the respective return runs 250, 27c inwardly along a path substantially closer to the respective fiber control runs 25a, 27a, than would be formed by the normal outwardly bowed return path of the apron from the zones of reversal 25b, 27b without the utilization of the external pressure guide elements 11a and 11b and utilizing internal guide elements as in conventional practice. Rotation of the rolls 13 and 15, the roll 15 being normally the drive roll effects pushing of the fiber control runs 25a, 27a forward away from the nip of the rolls and into the bulb-nose reversal zone, while withdrawing the apron at a corresponding rate from the bulb-nose reversal zones 25b, 27b and under the external deflecting guide elements 11a, 11!), along the apron returns runs 250, 270 to and about the rolls 13, 15. The result of this operation is to provide a truly resilient finger control on the fibers along substantially the entire length of the fiber control runs 25a, 27a without requiring utilization of internal tensor elements. In order to minimize any buildup of lint on the external guide ele ments 11a, 11b, it is an important feature that these guide elements be spaced apart sufficiently far apart across the width of the aprons as to be outside of the longitudinal path of travel of the fibers. In other words, if there is a single fiber drafting path without traverse such will normally be along the center portion of the length of the aprons and the raised knurled portions of the rolls, and guide elements 11a, 11b, need merely have their interfacing ends spaced apart on opposite sides of this path of fibers between the aprons. However, in order to employ a single cradle assembly for both traverse and nontraverse type drafting, or in other words irrespective of whether the fibers are traversed or passed in a single nontraversed substantially stationary line of travel between the aprons, it is desirable that the pins or other guide elements 11a, 11b, have their intersurfaces sufficiently spaced apart as to accommodate this traverse of the fiber flow path without creating the likelihood of contact of adhering fibers on the apron from the fiber flow path coming into contact with the guide elements 11a, 1112.

In some instances, particularly in the case of long fiber control runs 25a, 27a, it may be desirable to employ additional guide elements 11c for guiding the inner surface of the lower apron 27 along its intermediate flow path in order to minimize any possible tendency of separation of the aprons along this path. In this instance, it is also desirable that the guide elements lilc be disposed on opposite sides and out of the line of fiber flow path between the aprons.

It will thus be apparent that according to the embodiment of FIGURES 1-3 the upper apron 25 is driven in a counterclockwise direction and the lower apron 27 is driven in a clockwise direction as viewed in FIGURES 1 and 2, with the interfacing fiber control runs 25a and 27a being pushed forward toward the bulbous nose ends 25b, 2712, respectively, from which nose ends the aprons are continually withdrawn along the return runs 250, 27c to and about the respective rolls 13, 15. The fiber flow path is maintained along the fiber control runs 25a, 27a and between the interfacing ends of the opposing external side guiding apron deflecting elements 11a, 11b, for each of the respective aprons. The natural elasticity of (the aprons, which are of rubber or other desired flexibly elastic material, together with the overall length of the aprons, will have a basic effect on the size and shape of the bulb noses 25b, 27b of the respective aprons, and this natural elasticity and tendency to recover on the part of the aprons will also be most advantageous in pressing the two aprons together along the length of the fiber control runs 250, 27c inasmuch as the aprons will attempt to assume as large a radius of curvature as possible, and the bulb noses 25b and 2712 are, of course, smaller than the largest possible radius of curvature. Since the aprons are in face-to-face relation along the fiber control runs 25a, 27a, they will in their tendency to assume a larger radius of curvature as an extension of the bulb nose zones 25b, 27b, resiliently bias themselves against one another along these fiber control runs for desired resilient and gentle control of the fibers along these runs. As a consequence of forming the pressure elements 11a, 11b, on opposite sides and out of the vertical plane of travel of the fibers between the aprons, it will be seen that there will be no fiber pickup and accumulation on these elements resulting from fibers which have adhered to the aprons from contact with the bundle of fibers passing between the aprons in their normal flow path.

In the alternative embodiment of FIGURE 4 the apron deflecting side guide pressure elements 1110, 1111), are canted. This canting of these elements may be advantageous in some instances in maintaining the apron in a centered position.

In the alternative embodiment of FIGURE 5 the side guide pressure elements 211a, 21112, are formed as rollers, to reduce the frictional action of these apron deflecting side guide elements on the apron travel. Otherwise, the structure and operation of this embodiment is substantially the same as that of FIGURES 13. If desired, the axes of rollers 211a and 2111) may be canted with respect to one another so that the free end of the rollers will be further from the apron fiber control run path than the supported end.

In the further embodiment of FIGURE 6 a single apron 325 is employed in conjunction with its respective roll 313, and the cradle 311, also shown in FIGURE 6a, takes the form in which two adjustable external apron pressuring and guiding elements in the form of side pins 311a, formed on positioning bars 336, which are adjustably mounted by a pair of screws 337 and washers 338 on engaging bridge element 327 to form a unitary external apron guiding structure and stationary fiber control run between rolls 315 and 316. Adjustability and interlocking is obtained by a slot 339 in each of positioning bars 336. Alternatively, the positioning bars 336 can be provided in a variety of heights and provided with keyed elements for fitting onto bridge 327 so that adjustabili-ty is achieved by selection of the particular positioning bars which will position the pins 311a with respect to apron 325 in a predetermined position. Bridge 327 has an upper surface 327a interfacing the fiber control run 325a of the single apron to provide the fiber control run. The fibers pass between the stationary guide surface 327a and fiber control run 325a of the apron, and it will readily be apparent that the apron is maintained in resilient dependent contact with the surface 327a as a function of the elasticity of the apron 325 and the size of the bulb nose portion 325b, which is proximate roll 314, as well as the distance between the respective guide pressure elements 311a and the guide surface 327a. It will also be apparent that pressure on the fibers at the area of the bulb nose portion 325!) can be adjusted by positioning the pins 311a forwardly or backwardly or upwardly or downwardly with respect to that portion and also that the pressure of the apron will diminish toward the rear end of the fiber control run 32711, which facilitates the passage of fibers into the zone between the two interfacings 325a and 327a, particularly inasmuch as the fiber mass is larger in this zone than it is in the zone near the nose end of the apron 3251) after substantial drafting has been effected thereon.

The cradle assembly 311 may be effectively maintained in position by engagement of the cradle with each of the two bottom rolls 315 and 316, and in this illustrative embodiment the cradle preferably includes two curved leg portions 331 and 333 which are formed of sufiiciently elastic material to permit them to be snapped into position between the rolls 315 and 316. These two leg portions preferably engage with and thus also serve to clean the surfaces of the rolls 315 and 316 along a desired extent thereof, and particularly along the fiber carrying portion thereof, or they may ride on the smaller diameter necks only of these rolls if desired. Lateral positioning of the cradle is provided by a shoulder 332 on each side of the cradle 311 which lap over the ends of the bottom roll 315 and the edges of fiber control run 325a. These shoulders also assist the positioning bars 336 in preventing the apron 325 from walking from one side to the other of roll 313.

In order to minimize any tendency of the fibers to wrap around the roll 315 during passage of the fibers between the rolls 313, 315, and toward the rolls 314, 316, it is desirable to employ a smooth surfaced roll 315 and an undercut 335 on the concave curved surface facing the roll 315 forming a clear space of approximately .010-.030" depth and approximately arc length between the periphery of the roll 315 and the adjacent interfacing portion of the undercut 335. The exact mode of operation of this undercut is not known, but such has been found most advantageous in the operation of a single apron embodiment of this nature.

The embodiments shown in FIGURES 7a, 7b, 8, 9a, 9b and 10 employ enclosed apron guiding systems which effectively precludes fibers from coming in contact with the inside surface of the apron or aprons employed in these systems and their respective rolls. These embodiments employ a roll top desk type of external apron surface guide means. The configuration of the tracking surface is such that a slight compressive loading force is exerted on the external face of the apron proximate both its edges along their complete periphery, thus providing a seal which keeps lint from the interior of the apron and its roll. As with the configurations of the other figures, a reverse curved configuration is imparted to the apron which produces a forward bulb-shaped nose configuration for the apron so that a snub bar is not required to keep the apron properly positioned.

Referring now specifically to the embodiment of FIGURES 7a, 7b and 8, this embodiment of the cradle assemblies of this invention employs a single apron 425 is employed in conjunction with its respective roll 413, which is slightly shorter in length than the width of the apron, and a cradle 411, similar to that shown in FIG- URES 6 and 6a, is employed as a stationary fiber control run. The positioning of the apron 425 is achieved by side plates 4110 and 411d formed of a resilient material such as polyformal or polyfiuorohydrocarbon, which are interconnected by an oval spacer element 421 mounted on side plate 411d to fit inside apron 425 without touching. On the free end of spacer element 421 is a locking element 421a which can be forced through slot 4211), which slot is shaped to snugly fit spacer element 421 and provide a locking fit with side plate 411a. A backing locking element 4210 prevents the rearward portions of plates 4110 and 411d from exerting too great a load on the apron 425. The side plates 4110 and 411d are each provided with recessed area 441 on their inside surface which is shaped so that the resulting shoulder 443 provides a tracking surface for the peripheral outer surfaces 426a and 426b of apron 425 which tracking surface causes the apron to conform substantially to the shape it would otherwise take as a result of being forced to assume a bulb nose shape at its forward portion 4251) because of the curve reversal portion 411:: and 41121 of the shoulders 443. Recessed area 441 of side plate 411d is provided with a further recessed round area 445 to provide a bearing for shoulder 413a of roll 413. Side element 4110 is provided with a round aperture 423 for mounting on shaft 41% of roll 413. Surrounding aperture 423 is a shoulder 424 extending upwardly from the recessed portion 441 to provide a bearing surface for the end 4130 of roll 413, thus keeping the rearward portion of the cradle assembly transversely positioned. A slit 447 passes through aperture 423 to the adjacent end of side plate 4110 so that the side plate can be snapped over shaft 41312, the slot being locked shut, when the side plate is properly mounted, by a snap locking means 447a. Both side plates 4110 and 411d are provided with an ear 436 provided with a vertical slot 439 for adjustably interlocking the side plates with respective sides of cradle 411 by means of a screw 437 passing through the vertical slot and a horizontal slot 438 in each side of the cradle. When all of the vertical and horizontal slots are positioned in alignment, a single bolt, passing through cradle 411, and nut can be employed for interlocking, rather than a pair of screws. Cradle 411, with the exception of slots 438 of FIGURE 70 and shoulders 332 of FIGURE 6a, has the same construction as cradle 311 shown in FIGURES 6 and 6a and is similarly arranged for engagement with rolls 415 and 416. Lateral forward alignment of side plates 411c and 411d is maintained by the overlapping of their forward portions with the ends of roll 414. As shown in FIG- URE 8, the peripheral length of shoulders 443 of the recessed portions 441 of side plates 4110 and 411d is such that the peripheral portions 426a and .2512 of the outer surface apron 425 are compressed slightly by shoulders 443, thus providing a continuous seal between the apron 425 and side plates 4110 and 411d which prevents lint from collecting on roll 413 or on the interior face of apron 425.

The embodiment of FIGURES 9a, 9b and 10 is designed for use in a double apron system and is also formed of a resilient material, such as a polyformal or polyfluorohydrocarbon. In this embodiment, the cradle 411 shown in FIGURE 7a has been replaced by an apron 527 whose upper surface 527a forms a moving bottom half of a fiber control run, with the lower surface 4250 of apron 425 forming the top half. The bottom half of side plates 5110 and 51101 are each shaped substantially in the same manner as their upper half to provide an apron guiding system for apron 527. The construction of the upper half of side plates 5110 and 511d is similar to that of the embodiment shown in FIG- URES 7a, 7b and 8 except that the further recessed portion 545 of plate 511d and the aperture 523 are vertically elongated to permit adjustment of rolls 513 and 515 with respect to each other. The lower half of side plates 5110 and 511d have generally the inverted shape of the upper half, each being provided with a slit 547 for slipping the side plate over shaft 515a of roll 515, and an aperture 554 for mounting the side plate on shaft 515a, a recessed area 541 to provide a shoulder 543 which, with curve reversal points 511a and 5111) and roll 515, determine the configuration assumed by apron 527. Slit 547 of side plate 511d is locked shut by snap locking means 547a whereas the corresponding slit of side plate 5110 is locked shut by snap locking means 551. A narrow wall 553 is provided between upper recessed portion 441 and lower recessed portion 541 of each side plate. As shown in FIGURE 10, one of these walls fits between the peripheral portions 426a and 42Gb of apron 425 and one fits between 528a and 52% of apron 527 so that these peripheral portions are compressed away from each other by shoulders 443 and 543, respectively, of the upper and lower halves of side plates 5110 and SIM. As with the embodiment shown in FIGURES 7a, 7b and 8, forward lateral positioning is maintained by the overlapping of the forward ends of side plates 5110 and 511d over the ends of roll 414 and, in this embodiment, also over the ends of roll 416.

While the invention has been described with respect to several illustrative embodiments constructed in accordance therewith it will be apparent that various modifications and improvements may be made without departing from the scope and spirit of the invention. Accordingly, it is to be understood that the invention is not to be limited by these specific illustrative embodiments, but only by the scope of the appended claims.

That which is claimed is:

1. A drafting assembly comprising two spaced-apart pairs of drafting rolls, an endless fiber-control apron disposed about one roll of one pair of said rolls and having a fiber control run, a return run and a reverse bend spaced from said one roll of said pair of rolls, a fiber supporting and guiding bridge element having oppositely extending concave surfaces in engagement with the peripheral surfaces of two successive rolls of said pairs of drafting rolls, said fiber supporting and guiding element having a substantially planar surface in opposed relationship to said fiber control run of said apron, and spaced apart guides provided with a recessed portion operably associated with said fiber supporting and guiding bridge element to deflect opposite lateral edge portion of the external surface of the return run of said apron, said recessed portion being on the side of spaced apart guides which face said apron and forming a pair of substantially identical continuous shoulders which provide tracking surfaces for the edges of said apron, said edges of said apron being located in said recesses.

2. The structure of claim 1 wherein the peripheral length of each of said shoulders is slightly less than that of said apron thus imparting a compressive loading on the outer surface of said apron along its edges and providing a continuous seal between said guides and said apron.

3. The structure of claim 2 wherein said concave surface in engagement with the roll in nip forming engagement with the apron carrying roll has an undercut portion to aid in minimizing roll lap-ups.

4. A drafting assembly comprising two spaced-apart pairs of drafting rolls, an endless fiber-control apron disposed about one roll of one pair of said rolls and having a fiber control run, a return run and a reverse bend spaced from said one roll of said pair of rolls, a fiber supporting and guiding bridge element having oppositely extending concave surfaces in engagement with the peripheral surfaces of two successive rolls of said pairs of drafting rolls, said fiber supporting and guiding element having a substantially planar surface in opposed relationship to said fiber control run of said apron, and spaced apart guides extending generally toward one another and operably associated with said fiber supporting and guiding bridge element to deflect opposite lateral edge portions of the external surface of the return run of said apron, the lateral side portions only of said apron external periphery being externally guided by said spaced apart guides and the lateral central portion of the external periphery of said apron being free of external guidance between said opposing spaced apart guides.

5. The structure of claim 4 wherein said spaced apart guides are opposing pins extending inwardly toward one another.

6, The structure of claim 5 wherein said concave surface in engagement with the roll in nip forming engagement with the apron carrying roll has an undercut portion to aid in minimizing roll lap'ups.

References ited b3, the Examiner UNITED STATES PATENTS 1,481,689 1/1924 Casablancas l9293 XR 1,494,991 5/ 1924 Casablancas l9--249 2,020,483 11/1935 Truslow 19-255 3,156,953 11/1964 Newton et a1. l9-245 FOREIGN PATENTS 104,818 3/1917 Great Britain.

MERVIN STEIN, Primary Examiner.

D. NEWTON, Examiner. 

1. A DRAFTING ASSEMBLY COMPRISING TWO SPACED-APART PAIRS OF DRAFTING ROLLS, AN ENDLESS FIBER-CONTROL APRON DISPOSED ABOUT ONE ROLL OF ONE PAIR OF SIAD ROLLS AND HAVING A FIBER CONTROL RUN, A RETURN RUN AND A REVERSE BEND SPACED FROM SAID ONE ROLL OF SAID PAIR OF ROLLS, A FIBER SUPPORTING AND GUIDING BRIDGE ELEMENT HAVING OPPOSITELY EXTENDING CONCAVE SURFACES IN ENGAGEMENT WITH THE PEREPHERAL SURFACES OF TWO SUCCESSIVE ROLLS OF SAID PAIRS OF DRAFTING ROLLS, SAID FIBER SUPPORTING AND GUIDING ELEMENT HAVING A SUBSTANTIALLY PLANAR SURFACE IN OPPOSED RELATIONSHIP TO SAID FIBER CONTROL RUN OF SAID APRON, AND SPACED APART GUIDES PROVIDED WITH A RECESSED PORTION OPERABLY ASSOCIATED WITH SAID FIBER SUPPORTING AND GUIDING BRIDGE ELEMENT TO DEFLECT OPPOSITE LATERAL EDGE PORTION OF THE EXTERNAL SURFACE OF THE RETURN RUN OF SAID 